function fakeAsync(){
  let delay = Math.random() * 100;
  console.log(delay);
  return new Promise((resolve,reject)=>{
    setTimeout(()=>{
      console.log('Async taks use '+delay+'ms');
      resolve(delay);
    },delay);
  })
}

console.log('start...');

//检测异步任务是否正确
//(async ()=> {
//  await fakeAsync();
//})();

module.exports=fakeAsync;
